Car phone

A car phone is a mobile radio telephone specifically designed for and fitted into an automobile. This service originated with the Bell System and was first used in St. Louis, Missouri, on June 17, 1946.

Motorola Car Telephone Model TLD-1100, 1964

Overview

United States

The original equipment weighed 80 pounds (36 kg), and there were initially only three channels for all the users in the metropolitan area (other sources claim six channels).

On October 2, 1946, Motorola communications equipment carried the first calls on Illinois Bell Telephone Company's new car radiotelephone service in Chicago. Due to the small number of radio frequencies available, the service quickly reached capacity.

In 1964 AT&T introduced the Improved Mobile Telephone Service (IMTS). More licenses were added, bringing the total to 32 channels across three bands (See IMTS frequencies). This service was used at least into the 1980s in large portions of North America.

In 1968, almost 22 years after the initial network, the US government started to consider reserving spectrum for land mobile radio communication, to be used by private persons. The FCC initiated proceedings which resulted in the reservation of 75 MHz of spectrum in 1970. During the 1970s the FCC changed its mind a few times, such as in 1974 when it reduced the spectrum to 40 MHz.

On May 4th, 1981 the FCC released the rules for providing commercial cellular service. Over the next few years the FCC received hundreds of applications for 90 markets. The first cellular system went live on October the 13th 1983 in the Chicago market.

Finland

In Finland, car phone service was first available in 1971 on the zero generation ARP (Autoradiopuhelin, or Car Radiophone) service. This was succeeded in 1982 by the 1G system NMT (Nordic Mobile Telephone), used across Scandinavia and in other often remote areas.

Sweden

Sweden started relatively early with plans for mobile telephony service trials at the end of the 1940s. At the end of the 1950s, a trial system was built, using two channels, providing service for five mobile stations. In 1956, two commercial systems were brought online, each equipped with four channels. There were 125 subscribers by the end of the 1960s, when the network was shut down.

Meanwhile, other mobile networks were built in the 1960s and later on, and plans were made for future networks, cumulating in the cooperation for the NMT system.

Germany

West Germany

AEG 4015C telephone for the German B network c. 1979

In West Germany, the car phone service was first released in 1958 as the A-Netz service (Netz being German for network). In 1971, it reached its capacity limit of almost 11,000 subscribers and was succeeded by the B-Netz in 1972, which featured direct dialing rather than a human operator to connect calls. However, in order to reach a subscriber, one would still need to know their location since the handset would assume the local area code of the base station serving it. It was succeeded in 1985 by the C-Netz 1G system.

The C-Netz was replaced by the D-Netz, a 2G GSM system, starting in 1992. With two licensees, one building and operating the D1-Netz, the other one building and operating the D2-Netz. Both on the 900 MHz band. The D-Netz was later complemented, not replaced, by the E-Netz. Again two licenses were granted for an E1-Netz and an E2-Netz, and the technology was called DCS 1800 - a GSM variant for the 1800 MHz band. These D-Netz and E-Netz networks were where the main shift from car phones towards mobile (handheld) phones occurred.

East Germany

East Germany did develop an analog radio phone network. It was called URTES-Netz (UHF-Radio-Telefonie-System network). But the network was never used in East Germany (with one notable exception) due to fear by the Stasi of not having control over the communication.

In 1979 Mexico was looking for a radio phone network and awarded East Germany with the contract. Over a period of 17 month the system was then developed in East Germany from scratch and the equipment produced in East Germany. It was installed in 1981 in Mexico with a maximum capacity of 120 stations. The stations were given the type designation UDS 721 U. The call signs used during testing were Blaumeise (blue tit) followed by a number. A station weighted approximately 10 kg.

Typically the stations were installed at fixed locations in rural areas. However, one station was reportedly installed by request of the governor of Guerrero, Alejandro Cervantes Delgado in his car, making it the first, and possible only car phone in the network. A prototype of that telephone was briefly shown in a TV report about the development of the URTES network.

Later on additional URTES networks were built in Mexico and other countries, in total half a dozen or so.

There was a significant lack of fixed network telephone capacity in East Germany after the East German state collapsed. One attempt to bridge the gap was to use an URTES network in East Germany, making it the only live deployment of such a network where it was originally developed. However, the West German analog C-Netz was quickly extended to East Germany. The digital 2G D-Netz was also built in East Germany from 1992 onward. For a period of time C-Netz and later D-Netz car phones and lug-gable phones were a staple of business persons in East Germany.

United Kingdom

The UK started its TACS system in 1985. TACS was a modified version of the US AMPS system. TACS was replaced by GSM in the 1990s.

North America

In North America, car phones typically used the Mobile Telephone Service (MTS), which was first used in St. Louis, or Improved Mobile Telephone Service (IMTS) before giving way to analog cellular service (AMPS) in 1984. AMPS technology was discontinued in the United States in 2008.

Motorola car phone in the center console of a BMW 750iL

Since a traditional car phone uses a high-power transmitter and external antenna, it is ideal for rural or undeveloped areas where mobile handsets may not work well or at all. However, due to current US Federal Communications Commission regulations, carriers must pay penalties for activating any equipment that is not an E911 compliant device, such as analog.

In the 1980s, the car phone was more popular than the mobile phone. However, as mobile phones became lighter and more affordable during the mobile phone boom in the 1990s, car phones became less common. By the 2000s, car phones had become uncommon due to the convenience of mobile phones along with in-car mobile phone integrative technologies such as Bluetooth.

There were still some car phones available as recently as 2008, including the Nokia 810 and the Motorola VC6096 for use with GSM networks and a car phone made by NAL Research for the Iridium satellite network. Motorola provided US customers with the m800 and m900 car phones, for use with CDMA and GSM networks respectively. Some car phones had colour screens and supported high-speed data connections as well as the ability to access SIM cards stored in other phones via Bluetooth.

Since 2008, many automobiles have featured integrated, "hands-free" systems to utilize a consumer's mobile phone, via a Bluetooth wireless link or use an integrated transceiver. The systems use an internally mounted microphone, and the car's audio system, and may feature voice activation and control.

See also

• OnStar, emergency notification system

External links

• Media related to Automobile telephones at Wikimedia Commons